To Remember, We Must Forget

“In order to remember, we must forget. Recent research shows that when your brain retrieves newly encoded information, it suppresses older related information so that it does not interfere with the process of recall. Now a team of European researchers has identified a neural pathway that induces forgetting by actively erasing memories. The findings could eventually lead to novel treatments for conditions such as post-traumatic stress disorder (PTSD).

“We’ve known since the early 1950s that a brain structure called the hippocampus is critical for memory formation and retrieval, and subsequent work using modern techniques has revealed a great deal of information about the underlying cellular mechanisms. The hippocampus contains neural circuits that loop through three of its sub-regions – the dentate gyrus and the CA3 and CA1 areas – and it’s widely believed that memories form by the strengthening and weakening of synaptic connections within these circuits.

[…]

“This is the first time that a pathway in the brain has been linked to forgetting, to actively erasing memories,” said Gross, a co-senior author of the study. “One explanation for [our findings] is that there is limited space in the brain, so when you’re learning, you have to weaken some connections to make room for others. To learn new things, you have to forget things you’ve learned before.”

“The finding that memory loss can be induced by Npy1 receptor activation alone could one day help researchers to treat conditions involving intrusive traumatic memories. “A patient suffering from intrusive traumatic memories would take a pill containing a drug that would enter the brain and activate Npy1 receptors and then be exposed to a virtual experience of the trauma,” says Gross, “and we predict that the combination of receptor activation and trauma exposure and recall would promote the selective erasure of the relevant memory.”